Drywall tape has been used for many years to cover the joints or seams of abutting wallboards. A typical method for applying the tape to the seams is to press the drywall joint compound into the joint, spread it over the adjacent ends of the wallboards and then place the dry tape over the joint. Another coat of compound is then applied over the tape and, after the compound has dried, it is sanded to a smooth surface suitable for painting. Forcing a sufficient amount of compound into the seams while spreading an evenly distributed, thin coat on the edges of the wallboards has been a problem for the do-it-yourselfer and professional alike.
Application of too much or too little joint compound to the seam area may cause various problems such as bubbles under the tape, edge curling, or may require the drywall installer to spend an inordinate amount of sanding time to achieve the desired smooth surface at the joints of the drywall. Such problems not only increase the time of installation of the drywall but also cause aggravation to the installer as well as, and more importantly, reducing the profit structure of professional drywall installers operating in a competitive pricing environment. These problems also make it more difficult for a drywall installer to comply with minimum standards of the industry in the first phase of joint treatment in drywall installation.
Numerous dispensers have been developed for applying a substance to a strip of material prior to application of the strip to another surface, including drywall joint compound dispensers which apply compound to the tape prior to application of the tape on the seams of wallboards. Examples of these prior art dispensers are shown in U.S. Pat. Nos. 3,496,909; 3,513,809; 3,381,661; 3,292,575; 4,067,294; 1,935,060; 2,717,575; 2,679,232; 2,779,307; 4,159,695.
Although these known prior art dispensers serve their intended purposes, including providing solutions to many of the aforedescribed problems experienced in drywall installation, most of these dispensers require a separate hopper into which the joint compound or other substance must be transferred for dispensing onto the drywall tape or other strip material. Many of these hoppers and/or dispensers are complicated devices which are expensive to manufacture and are time-consuming and expensive to maintain in proper working condition since they include moving parts subject to wear which ultimately require repair or replacement. Furthermore, in others of these prior art devices and/or dispensers, the tape or other strip material cannot be pulled through the dispenser from a position above the exit slot of the hopper because this would cause the joint compound or other substance to be scraped from the tape or other strip material by vertically adjustable metering gates typically found near a tape or strip material exit slot. Also, in most of these dispensers, the full width of the tape or strip material is coated with the compound or other substance, respectively, when the tape or strip material exits the hopper. In many applications, including drywall taping, this is a desirable result because edge curling of the tape or strip material after application to the wallboards or other surface, respectively, is thereby prevented. However, presence of the joint compound or other substance along the edges of the tape or strip material when they are pulled from the exit slot of the hopper makes the tape or strip material more difficult and messy to handle.
A device similar in some respects to my invention is described in U.S. Pat. No. 4,367,692. The device of this patent does not require a separate hopper to dispense the joint compound, and is believed to be the closest known prior art. This patent discloses a dispenser in which drywall tape is coated with joint compound as the tape is pulled through tabbed slots in or associated with a container of the compound. In addition, the tape may be pulled through the container from a position above the exit slot of the dispenser without wiping the coating of compound off the tape. However, a pair of tabs at the exit slot of this device, while allowing pulling of the tape therethrough at any angle between 0.degree. and 75.degree. or even closer to vertical by urging the coated tape away from the top edge of the exit slot, do not prevent the edges of the tape from becoming coated with compound, a result which makes the tape messy and difficult to handle as mentioned above. If the tabs were moved to the outside margins of the exit slot, the edges of the tape would effectively be prevented from becoming coated with compound, but the center of the tape would contact the top edge of the exit slot causing the coating in the middle of the tape to be scrapped away, presumably the precise reason why the tabs are placed inwardly from the outer margin of the exit slot. Thus, although the device of this patent may solve the problem of compound becoming scraped from coated tape when the tape is pulled from the dispenser at an angle above a horizontal plane, it does little to remedy the problem of messy edges on drywall tape which makes application thereof more difficult.
There is no dispenser for applying a drywall joint compound to a strip of tape of which I am aware which utilizes the container in which the drywall joint compound is shipped and stored and that allows the tape to be pulled out of an exit slot subsequently formed in a sidewall of the dispenser at an angle above a horizontal plane without wiping the coating of compound off the tape, and which coats the tape in such a manner that the edges thereof remain relatively dry for ease of handling and application to the drywall.